From 5ec3f5d1277bfc9686ded94b3df5b4effeb49cd6 2017-11-15 16:20:12
From: Thibaud Rabillard <etude@mbp-de-etude.itlinkgroupe.fr>
Date: 2017-11-15 16:20:12
Subject: [PATCH] New style on mac to keep the scrollbars visible

---

diff --git a/gui/include/Visualization/MacScrollBarStyle.h b/gui/include/Visualization/MacScrollBarStyle.h
new file mode 100644
index 0000000..9ddebc3
--- /dev/null
+++ b/gui/include/Visualization/MacScrollBarStyle.h
@@ -0,0 +1,18 @@
+#ifndef SCIQLOP_MACSCROLLBARSTYLE_H
+#define SCIQLOP_MACSCROLLBARSTYLE_H
+
+#include <QProxyStyle>
+
+/**
+ * @brief Special style to always display the scrollbars on MAC.
+ */
+class MacScrollBarStyle : public QProxyStyle {
+
+public:
+    int styleHint(StyleHint hint, const QStyleOption *option, const QWidget *widget,
+                  QStyleHintReturn *returnData) const;
+
+    void selfInstallOn(QWidget *widget, bool installOnSubWidgets);
+};
+
+#endif // SCIQLOP_MACSCROLLBARSTYLE_H
diff --git a/gui/meson.build b/gui/meson.build
index 85fdd4e..a3bf57f 100644
--- a/gui/meson.build
+++ b/gui/meson.build
@@ -78,7 +78,8 @@ gui_sources = [
   'src/Visualization/VisualizationDragDropContainer.cpp',
   'src/Visualization/VisualizationDragWidget.cpp',
   'src/Visualization/AxisRenderingUtils.cpp',
-  'src/Visualization/PlottablesRenderingUtils.cpp'
+  'src/Visualization/PlottablesRenderingUtils.cpp',
+  'src/Visualization/MacScrollBarStyle.cpp'
 ]
 
 gui_inc = include_directories(['include'])
diff --git a/gui/src/Visualization/MacScrollBarStyle.cpp b/gui/src/Visualization/MacScrollBarStyle.cpp
new file mode 100644
index 0000000..57686a1
--- /dev/null
+++ b/gui/src/Visualization/MacScrollBarStyle.cpp
@@ -0,0 +1,40 @@
+#include "Visualization/MacScrollBarStyle.h"
+
+#include <QWidget>
+
+int MacScrollBarStyle::styleHint(QStyle::StyleHint hint, const QStyleOption *option,
+                                 const QWidget *widget, QStyleHintReturn *returnData) const
+{
+    switch (hint) {
+        case SH_ScrollBar_Transient:
+            return false; // Makes the scrollbar always visible
+        case SH_ScrollView_FrameOnlyAroundContents:
+            return true; // Avoid that the scrollbar is drawn on top of the widget
+        default:
+            break;
+    }
+
+    return QProxyStyle::styleHint(hint, option, widget, returnData);
+}
+
+void MacScrollBarStyle::selfInstallOn(QWidget *widget, bool installOnSubWidgets)
+{
+    // Note: a style can be installed on a particular widget but it is not automatically applied its
+    // children widgets.
+
+    QList<QWidget *> widgetsToStyle{widget};
+    while (!widgetsToStyle.isEmpty()) {
+
+        auto widget = widgetsToStyle.takeFirst();
+        widget->setStyle(this);
+
+        if (installOnSubWidgets) {
+            for (auto child : widget->children()) {
+                auto childWidget = qobject_cast<QWidget *>(child);
+                if (childWidget) {
+                    widgetsToStyle << childWidget;
+                }
+            }
+        }
+    }
+}
diff --git a/gui/src/Visualization/VisualizationTabWidget.cpp b/gui/src/Visualization/VisualizationTabWidget.cpp
index b706f40..136412e 100644
--- a/gui/src/Visualization/VisualizationTabWidget.cpp
+++ b/gui/src/Visualization/VisualizationTabWidget.cpp
@@ -5,6 +5,8 @@
 #include "Visualization/VisualizationGraphWidget.h"
 #include "Visualization/VisualizationZoneWidget.h"
 
+#include "Visualization/MacScrollBarStyle.h"
+
 #include "Variable/VariableController.h"
 
 #include "Common/MimeTypesDef.h"
@@ -55,6 +57,10 @@ struct VisualizationTabWidget::VisualizationTabWidgetPrivate {
 
     QString m_Name;
 
+#ifdef Q_OS_MAC
+    std::unique_ptr<MacScrollBarStyle> m_MacScrollBarStyle = std::make_unique<MacScrollBarStyle>();
+#endif
+
     void dropGraph(int index, VisualizationTabWidget *tabWidget);
     void dropZone(int index, VisualizationTabWidget *tabWidget);
     void dropVariables(const QList<std::shared_ptr<Variable> > &variables, int index,
@@ -68,6 +74,10 @@ VisualizationTabWidget::VisualizationTabWidget(const QString &name, QWidget *par
 {
     ui->setupUi(this);
 
+#ifdef Q_OS_MAC
+    impl->m_MacScrollBarStyle->selfInstallOn(ui->scrollArea, true);
+#endif
+
     ui->dragDropContainer->setPlaceHolderType(DragDropHelper::PlaceHolderType::Zone, "Zone");
     ui->dragDropContainer->layout()->setContentsMargins(0, 0, 0, 5);
     ui->dragDropContainer->addAcceptedMimeType(